Highly sensitive detection of volatile organic compounds by an adsorption/combustion-type sensor based on mesoporous silica

Recently, we developed a highly sensitive micro-gas sensor on a silicon micro-hot platform, which was operated by a pulse-heating mode. The gas-sensing was resulted from the flash combustion of the volatile organic molecules adsorbed on the catalytic sensing material during a non-heating period. In the present work, Pd-loaded mesoporous silica (Pd/m-SiO2) was used as an adsorption/combustion-type sensing material. The sensor showed a large response peak to toluene, which was much larger than that of the sensor using Pd/γ-Al2O3 catalyst. Thus, m-SiO2 can increase dramatically the sensitivity of this type of sensor.